This invention relates to methods of and devices for relieving strain on members.
More particularly, this invention relates to strain relief devices in hydraulic or electrical conductors or connections utilizing a heat shrinkable member or sleeve.
In electric plugs, for example, which comprise one or more connectors for connecting the pin or pins thereof to one or more cables, the connections may be subject to strains, for example, when an axial or longitudinal stress is applied to the cable. It has hitherto been proposed to relieve such strains by anchoring the cable to the plug body using, for example, a grommet or a clamp whereby any stress is transmitted to the plug body rather than to the connections. The use of a grommet has the disadvantage that an efficient anchorage to the plug body is not usually attainable and the use of a clamp has the disadvantage that usually at least two screws have to be tightened to clamp the cable, which is inconvenient.
The present invention overcomes the prior disadvantages by providing method and apparatus for relieving strain by shrinking or recovering a heat shrinkable member onto an electric cable, an hydraulic hose or the like. The strain relief device comprises a heat shrinkable sleeve (as hereinafter defined) and a member, such as an annular disk. The heat shrinkable sleeve has at a point along its length, preferably at or near an end thereof, a raised portion, preferably in the shape of a circular flange, which raised portion has been formed by heat shrinking the heat shrinkable sleeve onto the member, the member being heat stable below and at the temperature at which the article is shrunk and having an aperture therethrough so that the cable, hose or the like can be passed through the whole length of the heat shrinkable article.